Difference Between Typhus and Typhoid

Key Difference – Typhus vs Typhoid
 

Typhus and typhoid are two infectious diseases caused by bacteria that enter into the human body via contaminated food and arthropods respectively. Typhus is a collective name given to a group of diseases caused by the rickettsia species, and enteric fever (typhoid fever) is an acute systemic illness characterized by fever, headache, and abdominal pain.  The key difference between these illnesses is that typhus is caused by rickettsiae whereas typhoid is caused by Salmonella typhi and paratyphi.   

CONTENTS

1. Overview and Key Difference
2. What is Typhus
3. What is Typhoid
4. Similarities Between Typhus and Typhoid
5. Side by Side Comparison – Typhus vs Typhoid in Tabular Form
6. Summary

What is Typhus?

Typhus is a collective name given to a group of diseases caused by the rickettsia species.  These are small bacteria that are transmitted to the humans via arthropods such as body lice. Rickettsiae live in the alimentary tract of the arthropods and enter into the human body by the inoculation of arthropod feces during scratching. There is multisystem involvement with predominant vasculitis.

Clinical Features

There are main two groups of typhus as typhus fever group and spotted fever group.

Hard tick is the vector of spotted fevers on most of the occasions. An eschar develops at the site of bite following an incubation period of 4-10 days. There are high fever and myalgia with a maculopapular rash which later progresses into a petechial rash.

Typhus fever group is subdivided into three smaller subcategories as epidemic typhus, endemic typhus and scrub typhus that are transmitted by body louse, rodents and chiggers respectively. There is an incubation period of 1-3weeks after which there is a rapid and sudden onset of a febrile illness with associated myalgia and malaise. The patient usually has a severe headache with conjunctivitis. A measles-like rash appears on the fifth day with the symptoms of meningo-encephalitis may progress into a coma. Myocarditis, peripheral gangrene, pneumonia, and splenomegaly occur in the most severe stage of the disease. Oliguric renal failure can develop in the fulminant disease.

Diagnosis

Diagnosis is based on the clinical features. PCR can be used for the confirmation of diagnosis.

Treatment

Doxycycline or tetracycline can be given for 5-7 days. Ciprofloxacin is also effective.

What is Typhoid?

Enteric fever is an acute systemic illness that is  characterized by fever, headache, and abdominal pain. Typhoid and paratyphoid are two variants of enteric fever caused by Salmonella typhi and paratyphi respectively. The infectious agent is transmitted as a result of the consumption of contaminated water and food.

Clinical Features

Clinical features appear after an incubation period of 10-14 days.

• Intermittent fever
• Headache
• Abdominal pain
• Hepatosplenomegaly
• Lymphadenopathy
• Maculopapular rash
• If not treated, the patient can get complications such as intestinal perforations, lobar pneumonia, meningitis, etc.

Diagnosis

Definitive diagnosis can be done through the culture of organisms from blood samples obtained from the patient. Leucopenia is common but nonspecific.

Management

Nowadays, quinolones are the drug of choice in the management of enteric fever. Earlier cotrimoxazole and amoxicillin were also used, but their importance has gone down due to the emerging resistance against them.

What is the Similarity Between Typhus and Typhoid?

• Both diseases are infectious diseases caused by different groups of bacteria.

What is the Difference Between Typhus and Typhoid?

Typhus vs Typhoid
Typhus is a collective name given to a group of diseases caused by the rickettsia species.	Enteric fever (typhoid fever) is an acute systemic illness characterized by fever, headache, and abdominal pain.
Transmission
The infectious agent is transmitted by arthropods. Typhus fever group is subdivided into three smaller subcategories as epidemic typhus, endemic typhus and scrub typhus that are transmitted by body louse, rodents and chiggers respectively. Hard tick is the vector of spotted fevers on most of the occasions.	The infectious agent is transmitted by contaminated food and water.
Agent
Typhus is caused by rickettsiae	Typhoid is caused by Salmonella typhi and paratyphi
Diagnosis
Diagnosis is based on the clinical features. PCR can be used for the confirmation of diagnosis.	Definitive diagnosis is through the culture of organisms from blood samples obtained from the patient. Leucopenia is common but nonspecific.
Clinical Features
There is an incubation period of 1-3weeks after which there is a rapid and sudden onset of a febrile illness with associated myalgia and malaise. The patient usually has a severe headache with conjunctivitis. A measles-like rash appears on the fifth day with the symptoms of meningoencephalitis may progress into a coma. Myocarditis, peripheral gangrene, pneumonia, and splenomegaly occur in the most severe stage of the disease. Oliguric renal failure can develop in the fulminant disease.	Clinical features appear after an incubation period of 10-14 days. ·         Intermittent fever ·         Headache ·         Abdominal pain ·         Hepatosplenomegaly ·         Lymphadenopathy ·         Maculopapular rash If not treated, the patient can get complications such as intestinal perforations, lobar pneumonia, meningitis and etc.
Treatment
Doxycycline or tetracycline can be given for 5-7 days. Ciprofloxacin is also effective.	Nowadays, quinolones are the drug of choice in the management of enteric fever. Earlier cotrimoxazole and amoxicillin were also used, but their importance has gone down due to the emerging resistance against them.

Summary – Typhus vs Typhoid 

Typhus is a collective name given to a group of diseases caused by the rickettsia species.On the other hand, enteric fever is an acute systemic illness characterized by fever, headache, and abdominal pain.Typhus is caused by rickettsiae whereas typhoid is caused by Salmonella typhi and paratyphi.This is the difference between typhus and typhoid.

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Reference:

1.Kumar, Parveen J., and Michael L. Clark. Kumar & Clark clinical medicine. Edinburgh: W.B. Saunders.

Image Courtesy:

1.’Epidemic Typhus. Macular rash’By Geor Jochmann, (CC BY-SA 4.0) via Commons Wikimedia  
2.’Chlorination Graphic – Typhoid Fever’By U.S. Centers for Disease Control and Prevention – U.S. Centers for Disease Control and Prevention, Summary of Notable Diseases, 1997., (Public Domain) via Commons Wikimedia